This invention relates to slant axis rotary mechanisms employed as engines, pumps, compressors, or the like. More specifically, it relates to improvements in rotor constructions for such mechanisms.
Rotor construction in slant axis rotary mechanisms is relatively complex due to the number of constraints requiring simultaneous satisfaction. For example, in a slant axis rotary engine, the rotor must be well cooled while at the same time sufficiently rigid as to not deflect appreciably to thereby maintain high compression ratios. The rotor must be easy to assemble which, in a practical sense, requires that it utilize common fastener technology. Simultaneously, the split lines between the parts must not interfere with the assembly of seals carried by the hub or flange, and grooves or bores for receiving the seals must be located so as to be relatively easy to machine.
Conventionally, the approach to rotor fabrication wherein it is attempted to optimize each of the above requirements, includes the fabrication of the main body and a threaded retainer threadably received in the main body. The main body carries one side of the hub as well as the rotor flange. It additionally carries part of the opposite hub side while the retainer carries the remainder of that hub side. The hubs are, of course, spherical and require the presence of grooves to carry hub seals. If relatively fine threads are employed at the interface of the main body and the threaded retainer, insufficient strength is present. Conversely, if coarse threads are employed, assembly torque is high and it is difficult to obtain a precise desired torque during assembly.
Moreover, the hub seal grooves on the main body and the threaded retainer must intersect at very precise locations, the high assembly torque makes it difficult to properly orient the threaded retainer on the main body so as to achieve proper alignment. Similarly, bearing clearances are difficult to control because of the large torques involved during assembly.